Demetalation of hydrocarbon charge stocks with manganese nodule catalyst

ABSTRACT

THIS SPECIFICATION DISCLOSES A PROCESS FOR THE DEMETALATION OF HYDROCARBON CHARGE STOCKS CONTAINING METAL IMPURITIES. THE PROCESS COMPRISES CONTACTING SAID HYDROCARBON CHARGE STOCK WITH HYDROGEN AND WITH A CATALYST COMPRISING SALT WATER MANGANESE NODULES. THESE NODULES HAVE BEEN PREVIOUSLY WASHED WITH WATER HAVING A TEMPERATURE OF AT LEAST 125*F. AND A TOTAL SALTS CONTENT OF NOR MORE THAN 1000 PARTS PER MILLION OF A TIME SUFFICIENT TO INCREASE THE ACCESSIBLE SURFACE AREA OF THE NODULES.

United States Patent U.S. Cl. 208-251 H 9 Claims ABSTRACT OF THE DISCLOSURE This specification discloses a process for the demetalation of hydrocarbon charge stocks containing metal impurities. The process comprises contacting said hydrocarbon charge stock with hydrogen and with a catalyst comprising salt water manganese nodules. These nodules have been previously washed with water having a temperature of at least 125 F. and a total salts content of not more than 1000 parts per million for a time sufiicient to increase the accessible surface area of the nodules.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of our copending application Ser. No. 100,931 now U.S. Pat. No.

3,716,479, filed Dec. 23, 1970.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to the treatment of a hydrocar: bon charge stock and relates more particularly to the treatment of a hydrocarbon charge stock employing a manganese nodule catalyst to effect removal from the hydrocarbon charge stock of organo-metallic compounds.

Description of the prior art U.S. Pat. No. 3,214,236 discloses hydrogenation, desulfurization and denitrogenation as being conversion processes in which manganese nodules are catalytically useful. This patent also discloses that the manganese nodule catalyst can be a source of manganese and other valuable metals after :being spent in effecting the desired catalytic conversion.

U.S. Pat. No. 3,509,041 discloses the use of manganese nodules, after pretreatment by base exchange to bond hydrogen ions thereto, in hydrocarbon conversion reactions, specifically cracking, hydrocracking, oxidation, olefin hydrogenation, and olefin isomerization.

U.S. Pat. No. 3,330,096 discloses the use of manganese nodules for removing sulfur compounds from gases.

U.S. Pat. No. 3,471,285 discloses the selective separation of manganese and iron from manganese nodules which also contain cobalt and nickel by reducing the nodules at elevated temperatures and then leaching with an aqueous solution of ammonium sulfate.

SUMMARY OF THE INVENTION In accordance with the invention, a hydrocarbon charge stock containing metal impurities is demetalized by contacting the charge stock with hydrogen, in the presence of, as a catalyst, salt water manganese nodules. These salt water manganese nodules have been previous- 3,813,331 Patented May 28, 1974 p CC 1y washed with water having a temperature of at least F. and a total salts content of not more than 1000 parts per million. The washing is continued for a time suificient to increase the accessible surface area of the nodules.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Various hydrocarbon charge stocks such as crude petroleum oils, topped crudes, heavy vacuumgas oils, shale oils, oils from tar sands, and other heavy hydrocarbon fractions such as residual fractions and disti'llates contain varying amounts of non-metallic and metallic impurities. The non-metallic impurities include nitrogen, sulfur, and oxygen and these exist in the form of various compounds and are often in relatively large quantities. The most common metallic impurities include iron, nickel, and vanadium. However, other metallic impurities including copper, zinc, and sodium are often found in various hydrocarbon charge stocks and in widely varying amounts. The metallic impurities may occur in several different forms as metal oxides or sulfides which are easily removed by single processing techniques such as by filtration or by water washing. However, the metal contaminants also occur in the form of relatively thermally stable organo-metallic complexes such as metal porphyrins and derivatives thereof along with complexes which are not completely identifiable and which are not so readily removed.

The presence of the metallic impurities in the hydrocarbon charge stocks is a source of difficulty in the processing of the charge stocks. The processing of the charge stock, whether the process is desulfurizing, cracking, reforming, isomerizing, or otherwise, is usually carried out in the presence of a catalyst and the metallic impurities tend to foul and inactivate the catalyst to an extent that may not be reversible. Fouling and inactivation of the catalyst are particularly undesirable Where the catalyst is relatively expensive, as, for example, where the active component of the catalyst is platinum. Regardless of the cost of the catalyst, fouling and inactivation add to the cost of the processing of the charge stock and therefore are desirably minimized.

Demetalation of the hydrocarbon charge stock can be effected by thermal processing of the charge stock. However, thermal processing results in conversion of an appreciable portion of the charge stock to coke and the portion of the charge stock converted to coke represents a loss of charge stock that desirably should be converted to a more economically valuable product or products. Moreover, by thermal processing, the metallic impurities tend to deposit in the coke with the result that the coke is less economically desirable than it would be in the absence of the metals.

Demetalation can also be effected by catalytic hydroprocessing of the charge stock. However, catalytic hydroprocessing results in the catalyst becoming fouled and inactivated by deposition of the metals on the catalyst. There is no convenient way of regenerating the catalyst and it ultimately must be discarded. Since these catalysts are 7 relatively expensive, catalytic hydroprocessing to demetallize hydrocarbon charge stocks has suffered from adverse economics.

In our aforementioned copending application, Ser. No. 100,931, there is disclosed a process for demetalation of a hydrocarbon charge stock employing hydrogen in the presence of, as a catalyst, a material derived from the naturally-occurring underwater deposit known as an manganese nodule. As disclosed in the copending application, an economical and elfective demetalation of a hydrocarbon charge stock is obtained. Manganese nodules are readily available in large quantities and are relatively inexpensive. Further, material derived from the nodules is capable of effectively removing the metallic impurities from a hydrocarbon charge stock. Thus, whereas the material obtained from the manganese nodules becomes fouled and inactivated by the demetallizing process, the material is obtainable at such low cost that the fouled and inactivated material can be discarded without significant effect on the economics of the dernetallizing process.

Manganese nodules, as is known, are naturally-occurring deposits of manganese, along with other metals, including iron, cobalt, nickel, and copper, found on the floors of bodies of water. The body of water may be that of salt water such as in the seas or oceans or may be relatively fresh water such as in lakes. Thus, for example, they are found in abundance on the floor of the Atlantic and Pacific Oceans and on the floor of Lake Michigan. By salt water manganese nodules, we mean those found on the floor of bodies of salt water such as the Atlantic and Pacific Oceans.

Our present invention is predicated upon our discovery that the catalytic activity of salt water manganese nodules for demetalation, and desulfurization, can be improved by washing the nodules with water. The washing is carried out with water having a temperature of at least 125 F. Further, the water has a total salts content of not more than 1000 parts per million.

The reason why washing of the salt water manganese nodules with water having a temperature of at least 125 F. and a total salts content of not more than 1000 parts per million improves the catalytic activity of the nodules is not thoroughly understood. This washing effects an increase in the accessible surface area of the nodules. By accessible surface area, we mean the surface area of the nodules which the hydrocarbon charge stock is able to contact. It also effects reduction in the chloride content of the nodules. Whether the increase in the accessible sur face area or the decrease in the chloride content, or both, is the essential factor in improving the catalytic properties of the salt water manganese nodules is not known. However, while it is not intended to limit the invention to the consequences of any theory, it is believed that the improvement in the catalytic activity of the nodules is due to the increase in the accessible surface area.

As stated, washing is carried out with water having a temperature of at least 125 F. With this temperature, improvement in the catalytic activity of the salt water manganese nodule is obtained. Higher temperatures, however, are preferred. For example, the temperature of the water employed for washing is preferably about the boiling temperature, namely about 212 F. Still higher temperatures may be employed where the washing is carried out under higher conditions of pressure.

The water employed for washing has a total salts content of less than 1000 parts per million. Satisfactory improvement in the catalytic activity of the nodules is obtained with water having this total salts content. For example, .the water may have a total salts content of not more than 500 parts per million. Preferably, fresh water is employed, i.e., potable water. Distilled water may also be employed.

By ,washing is meant contacting the salt water manganese nodules with the water. With contacting, a d1? fusion of'the water into the nodules occurs. Further, a diffusion of a solution of salts out of the nodules occurs. Thus, washing can be effected by immersing the manganese nodules in the wash water. Immersion may be effected one or more times employing new wash Water for each immersion. Preferably, in washing, the manganese nodules and the wash water are moved relative to each Other- Thus, where Washing iS effected by immersion, the

wash water may be stirred or otherwise agitated 'with the manganese nodules being stationary or both the wash water and the manganese nodules may be moved relative to each other by stirring sufliciently vigorously to move the manganese nodules as well as the wash water. The mixture of manganese nodules and wash water may also be tumbled to effect relative movement as by rocking or otherwise effecting oscillating movement of the container holding the manganese nodules and the wash water. Washing may also be effected by passing the water over the manganese nodules as by passing the Water through a bed of the nodules. Washing may also be effected by immersing the manganese nodules in the wash water and subjecting the wash water to boiling. A particularly effective way of washing the manganese nodules is by Soxhletextraction.

The time of washing should be suflicient to efiect a significant increase in the accessible surface area of the manganese nodules. By significant increase is meant an increase suflicient to effect a measurable improvement in the catalytic activity of the nodules.

The time of washing to effect any desired degree of increase in the accessible surface area of the nodules will depend upon the temperature and the total salt content of the water. It will also depend upon the volume of the wash water relative to the volume of the manganese nodules and the degree of movement of the wash water relative to the nodules With higher temperatures and lower total salt content, shorter times may be employed. Similarly with greater volumes and greater degree of movement, shorter times may be employed. Generally, any time of washing of at least 5 minutes Will increase the accessible surface area of the nodules sufiiciently to effect a measurable improvement in the catalytic activity of the nodules.

Prior or subsequent to the washing, the manganese nodules can be crushed and sized to obtain a desired particle size depending upon the type demetalation operation employed, for example, a fixed bed operation, an ebullition operation, or otherwise.

The demetalation reaction is carried out by contacting the hydrocarbon charge stock simultaneously with the catalyst and with hydrogen. The temperatures at which the reaction is carried out can be from about 650 F. to about 850 F. At the higher temperatures, a greater degree of demetalation occurs. However, the temperature employed should not be so high as to effect an undesirable degree of alteration of the charge stock. Preferably, the temperatures employed are in the range of 750-850 F. The pressures at which the reaction is carried out can be from about to about 3000 pounds per square inch gage (p.s.i.g.). Preferably, the pressures employed are in the range of 500-2000 p.s.i.g. Where the reaction is carried out by passing the hydrocarbon charge stock through a bed of the catalyst, the liquid hourly space velocity (LHSV) of the charge stock can be from about 0.2 to 4, preferably 0.5 to 2, volumes of charge stock per volume of catalyst per hour. Hydrogen circulation is at rates of 200015,000, preferably 500010,000, standard cubic feet of hydrogen per barrel of hydrocarbon charge stock. The hydrocarbon charge stock along with the hydrogen may be passed upwardly through a fixed bed of the catalyst in an upfiow reactor or may be passed downwardly through a fixed bed of the catalyst in a downflow trickle-bed reactor. The reaction may also be carried out by passing the charge stock and the hydrogen through an ebullient bed of the catalyst. The reaction may also be carried out by contacting the charge stock, the hydrogen, and the catalyst in a batch reactor.

The process of the invention may be employed for the demetalation of any hydrocarbon charge stock containing organo-metallic compounds. Ordinarily, these will be hydrocarbon charge stocks containing sufficient metal to cause difiiculty in the processing, or other subsequent use, of the charge stocks. Other subsequent use of the charge stocks can include burning of the charge stock as fuel wherein the metals cause corrosion problems. These charge stocks include whole crude petroleum oils, topped crude oils, residual oils, distillate fractions, heavy vacuum 6 in angstrom units (A.), and the chloride content in weight percent (wt. percent).

TABLE I gas oils, shale oils, oils from tar sands, and other heavy Catalyst A B c hydrocarbon oils. Charge stocks derived from Mid-Con- Surface area (mi/g.) 277 29g 3g; tinent and East Texas crudes contain small amounts of Zggg3g 3t{g;} 1122? 11223 {$89 metals. For example, some East Texas crudes contain Real density (g./ce.) 3.377 3.323 3.523 about 0.1 part per million of vanadium and 2-4 parts per gg lggiglggg zgtg 53 0,02 02 million of nickel. Charge stocks derived from West Texas crudes and foreign crudes, however, can contain larger It will be noted f Table I that hi d d amounts of metal- Kuwait Crude can contain Over 32 the chloride content of Catalyst A from 0.89% to 0.02% parts per million of vanadium and over 9 parts per million in the case f both catalysts B and C. However, it will of nickel While Venelufilah crudes can cohtalh 200400 also be noted that the additional Soxhlet washing received Pdrts P million of Vanadium and 17 to 59 Parts Per by Catalyst C did not reduce its chloride content below mill n f nickelthat of Catalyst B. However, the Soxhlet extracts were The Process of the Invention can be harmed out In evaporated to dryness and the recovered material repreiunction with Subsequent steps f processing of the y sented removal of about 2% by weight of solids from carbon charge Stock- For example, the hydrocarbon the nodules. It is believed that these solids removed during marge Stock can he Subsequently PIocessed for removal the extended Soxhlet washing of the nodules were slightly of sulfur and/or nitrogen. Further, for example, the hy- Soluble alumlnates and i1i drocarbon charge stock can be subsequently processed y The three catalysts were employed in the demetalation catalytic Cra i gof a hydrocarbon charge stock, namely, a Kuwait atmosh following examples will he illustrative of the pheric residual oil. This oil had the characteristics given vennon. in Table II. In this table, gravity is given in degrees Amer- Ple I lean Petroleum Institute (API), the amounts of sulfur, nitrogen, carbon and hydrogen and the Conradson Carbon This example will be illustrative of the effect of washing Residue in Weight pal-Cant (Wt Percent), and the amounts on the catalytic effect of manganese nodules from the Atf iron (Fe), k l Ni), d vanadium (V) in parts per lantlc Oceanmillion (p.p.m.).

A sample of manganese nodules obtained from the TABLE H Blake Plateau in the Atlantic Ocean was crushed. A por- Gravity API) 4 tion of this material was sieved to 14-30 mesh, U-S- S lf (Wt. Percent) 3 g9 Standard Sieve Series, and was designated Catalyst A- Nltrogen (wt percent) 019 Another portion of the crushed material was washed comadson Carbon Residue (wt percent) 723 with boiling water, i.e., at a temperature of 212 F., three carbon (wt percent) 5 times, each wash being of four minutes duration. Wash- Hydrogen (wt Percent) ing was effected by suspending the crushed material in 3 Fe (mum) 43 basket and immersing the basket containing the crushed Ni (plum) 12 material in boiling distilled water, new water being used V (ppm) 5 for each wash. The washed material was dried and sieved to 1430 mesh. A portion of this material was designated Demetalation was carried out by passing the oil Catalyst B. The remainder of this washed material was through a downflow trickle-bed reactor along with hythen extracted With distilled water in a Soxhlet extractor drogen for over 90 hours. Reaction conditions were as for 44 hours. Thereafter, the Soxhlet extracted material follows: was dried and sieved to 14-30 mesh. This latter material was designated Catalyst C. LHSV Each of Catalysts A, B, and C was analyzed for sur- Temperature, 775 face area, pore volume, particle density, real density, Hydrogen clrculanon rate x loooo average pore diameter, and chloride content. These prop- Pressure 1000 erties are set forth in Table I. In this table, and in the Th r lt are given for each of Catalysts A, B, and C in subsequent tables, surface area is given in square meters Tables III, IV, and V, respectively. In these tables, the per gram (m. /g.), pore volume in cubic centimeters per time on stream is given in hours (hrs.). The desulfurizagram (cc./g.), particle density and real density in grams tion and demetalation are given as percent (percent) dcper cubic centimeter (g./cc.), the average pore diameter sulfurization and demetalation.

TABLE III.RESULTS WITH CATALYST A Sample 1 2 3 4 5 6 7 8 9 Time on stream (hrs) 2 10.5 21 33 45 57 69 81 91 Liquid properties:

Gravity (*API) 20.3 20.3 20.3 20.3 20.3 20.3 20.3 Sulfu 3.05 3. 50 3.00 3.72 10 11 11 11 12 11 11 m.) 25 34 35 37 37 3s 3s 39 .2 .94443 43 43 50 49 50 Percent desulfurization .4 2.6 6.2 10.0 5.9 4.4 Percentdemetalation (Ni+V)- 63.4 39.8 241 20.7 17.2 17.2 13.8 15.5 13.8

TABLE IV.RESULTS WITH CATALYST B Sample 1234507s9 20.7 20.7 20.7 20.7 20.7 20.7 20.7 3.34 ..3.36 3.40 3.45 3.53 3.48 .7 3.7 0.3 10 11 11 11 11 v (p.p.m .4 20 23 2s 2s 29 29 20 (N1+v) p.m .1 27.4 34 7 35.3 33 30 40 40 40 Percent desulfunzation 40.1 28.0 1 13.6 12.6 11.3 9.3 10.5 Percentdemetalation(Ni+V) 75.7 52.3 402 33.3 34.5 32.3 31.0 31.0 31.0

TABLE V.-RESULTS WITH CATALYST Sample 1 2 3 4 6 6 7 8 9 Time onstream (hrs) 2 10.5 21 33 45 57 69 81 91 Liquid properties:

Gravity (API) 23.2 21.3 21.2 21.2 21.2 21.2 21.1 21.1 21.1 Sulfur (wt. percent)-.- 2.46 2.96 3.09 3.10 3.13 3.12 3.16 3.07 3.06 Ni {p.pm.) 2.7 6.5 7.9 8.4 8.8 9.4 9.8 9.8 9.8 V(p.p.m. 5.9 13 18 21 22 23 24 24 24 (Nl-l-V)(p.p.m.) 8.6 19.5 25.9 29.4 30.8 32.4 33.8 33.8 33.8 Percent desulfurization 36.8 23.9 20.5 20.3 19.5 19.8 18.8 21.1 21.3 Percent demetalation (Nli-V)-.-- 85.2 66.3 65.3 49.3 46.9 44.1 41.7 41.7 41.7

It will be observed firom Tables III, IV, and V that the demetalation activity of Catalyst B was greater than The two catalysts were employed for the demetalation of the same residual oil and at the" same reaction condithat of Catalyst A and that of Catalyst C greater than 15 tions described in Example 1. The results are given in that of Catalyst B. The average demetalation for Cat- Tables VII and VIII.

TABLE VIL-RESULTS WITH os'ranys'r n Sample 1 2 3 4 B 7 8 9 Time on stream 011's.) 2 l0. 5 21 33 45 57 69 81 91 TAB LE VIII.-RESULTS WITH CATALYST E Sample 1 2 3 4 5 6 7 8 9 Time on stream (hrs) 2 10. 5 21 33 67 69 81 91 Liquid properties:

Gravity (API) 24. 2 21. 6 20. 7 21. 3 21. 1 21. 1 20. 8 20. 8 20. 8 Sulfur (wt. percent) 2. 26 2. 91 3. 02 2. 95 2. 98 3. 01 3. 02 2. 99 2. 95 N1 (p.p.rn.) 2. 5 6. 9 8. 0 8. 3 9. 5 9. 7 9. 3 9. 8 9. 4 .m 2. 7 9. 8 13. 0 13.0 14. 8 l6. 4 16. 7 19. 8 19. 2 5. 2 16. 7 21. 0 21. 3 24. 3 26. 1 26. 0 29. 1 28. B 41. 9 25. 2 22. 4 24. 2 23. 4 22. 6 22. 4 23. 1 24. 2 91. 0 71. 2 63. 8 G3. 3 58. 1 55. O 5. 2 49. 8 50. 7

alysts A, B, and C was 22.8%, 3 8.7%, and 50.3%, respectively, indicating the efiectiveness of the washing applied to' Catalyst B and the additional elfectiveness of the Soxhlet washing applied to Catalyst C. Stated otherwise, as indicated in Tables III, IV, and V, the depth of washing has a major influence on the demetalation activity of the nodules. It will also be observed from Tables III, IV, and V that washing also significantly improved the desulfurization activity of the nodules.

Example 2 This example will illustrate the effect of washing on the catalytic effect of manganese nodules from the Pacific Ocean.

Manganese nodules obtained from the bottom of the Pacific Ocean were crushed and were washed three times with boiling distilled water, the washing being carried out in the manner and for the times described in Example 1. The nodules were then dried and sieved to 14-30 mesh. A portion of the dried material was designated Catalyst D. The remainder of the dried material was extracted in a Soxhlet extractor with distilled water for 71 hours. The extracted material was dried and resieved to 14-30 mesh. This material was designated Catalyst E. The properties and chloride content were determined and are given in Table VI.

It will be noted from Tables VII and VIII that washing of the nodules improved their catalytic activity for demetalation. It will also be noted that washing of the nodules approximately doubled their activity for desulfurization.

We claim:

1. A process for the demetalation of a hydrocarbon charge stock containing metal impurities comprising contacting said hydrocarbon charge stock with hydrogen and with a catalyst comprising salt water manganese nodules which have been Washed with water having a temperature of at least 125 F. and a total salts content of not more than 1000 parts per million for a time suflicient to increase the accessible surface area of said nodules.

2. The process of claim 1 wherein said manganese nodules are nodules from the Atlantic Ocean.

3. The process of claim 1 wherein said manganese nodules are nodules from the Pacific Ocean.

4. The process of claim 1 wherein said nodules are washed with water having a temperature of about 212 F.

5. The process of claim 1 wherein said nodules have been washed by Soxhlet extraction.

6. The process of claim 1 wherein said nodules have TABLE VI been washed with water having a total salts content of 08mm D E not more than 500 parts per million. g j ggfi gagg fig 7. The process of claim 1 wherein said nodules have Particle de s y (ts-lee}--- 35 been washed with fresh water.

252 gagiffi; tij jj '46 8. The process of claim 1 wherein said nodules have cmm'ide mint percent) been washed with distilled Water.

9 10 9. The process of claim 1 wherein said nodules have 3,471,285 11/1969 Rolf 75--115 been washed for at least 5 minutes. 3,509,041 4/1970 Miale 208-419 References Cited DELBERT E. GANTZ, Primary Examiner UNITED STATES PATENTS 5 J. M. NELSON, Assistant Examiner 3,716,479 2/1973 Weisz et a1. 208211 US. Cl. X.R.

3,214,236 11/1965 Weisz et a1. 252-471 208211; 252-454 UNITED STATES PATENT OFFICE CERTIFICA'IIC OF (.OR'REUIION Patent No- 3 813 ,33]. Dated May 28 1974 lnventofls) Paul B. Weisz and Anthony J. Silvestri It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 67, "as an" should read --as a Column 4, line 38, after "type" insert --of--; 7

line 46, "temperature" should read -temperatures--.

Column 7, Table VI, last line, 00.1" should read Column 9, and column 10, two of the references cited should read: 3,214,236 10/1965 Weisz 2 2-471 3,471,285 10/1969 Rolf 75-115 Signed and sealed this 1st day of October 1974.

(SEAL) Attest:

MCCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents FORM PO-105O (10-69) USCOMM-DC 60376-P69 fi U.S. GOVERNMENT PRINTING OFFICE: 19.9 O366-334 

